Percy b



'To all whom 'it mary concern; s

Be it` known that I, PERcY B. MEYER, a

citizen of the United States, residin at Shreveport, in the parish'of Caddo and tate of Louisiana, have invented certain new land posed to provide a gas check against the pas' sage of the flame and gases between the projectile and 'gun by means of a band or ring of ductile metal carried by' the projectile'in addition to the usual rifle motion imparting band and adapted to be forced into engagement with the rifling grooves in the gun, so as to close such grooves immediatel u on the explosion of the charge. But to t e est of my knowledge, such constructions have not been successful in attaining the end-desired, and this result is due principally, I believe, to the fact that u on the explosion of the cha e, the projecti e must travel in the bore of t e a distance lnearly equal to its length before-the as check ring, situated at the butt end of t e projectile, engages the ed grooves in the gun, thus permitting the flame and ases during such interval to escape past t e ring and pass between the surface of the projectile and the bore of the n, to the consequent erosion of the bore. T ere is objection also to the smalll circumferential band now employed either when used singly as both the rotary motion imparting member and gas check, or when used in pairs to effect,

these two objects, due to the danger of these bands, owing to their size, being melted or stripped before the rifl motion is given to the'projectile and their failure to `properly engage the grooves in a gun whose bore 1sv eroded from previous irings, whereby both the pro er rifle motion of the projectile is lost, an also there results a great loss of velocity on account of winda e. My invention to overcome this d' culty and to this end provides means whereby immediately upon the explosion of the charge and at the beginning of the forward movement of the projectile, a gas sealing enga ement between the lands o the gun an corresponding fgrooves cut in the projectile is effected so I Bpedcation of Letters Patent. i Application Med January 25, 19,08` Serial No. 418,577.

' l, :unanimi ad, 190s..

that the passageof flame and between the projectile and'bore of the gun proef,y

. vented.

In cari-yin out my invention, it is embodied in prei inafter described and illustrated in the accompanyin drawings.

1n these of a projectile containing my im rovemente; Fig. 2 is a longitudinal section o a gun and a projectile vseated in the bore of the 4and ready for firing; Fig.l 3, an enlarged detail view similar to Fig. 2 Fig. 4, a cross section through rojectile and and Fig. 5, a view simi ar to Fig'. 4, o a modification.

Referring to the drawin to Figs. l .to 4, 1 is ane ongatedprojectile of usual form adapted to be loaded at the breech of a gun 2. Formed in this 'projectile numerous, but in order to render more inlan ing grooves 3 of the projectile as few in num.- ber and as greatl lexa gerated in.size. The' ooves 3 exten at t e same itch as" the'- ands in the bore and serve by t eir ellgage-r ment with 'the lands to 've the rot' tory, rifle motion to the projecti e. These grooves` are so formed that at the same time'they perform the main function ofl {inventiom namely, of providing a close sea 'ng'contac't between the projectile and gun which takes place from t e very instant of firing, and

rawlngs, 1 is a plan view l e grooves 3, which are adapt"- erable formin'the device -here-v and particularly tellciible my invention, VI have shown theV i s 4 in the bore of the gun and the engagwhich is effected along the entire length of j that part of the projectile of maximum diam.- eter. To accomplish these purposes the ooves 3 extend from the base of the projectile along the portion 5, of maximum and uniform diameter, substantially to the limit of such portion, at'6, Where the shell begins to taper off to the point. ment, when the projectile is in the firing chamber, as shown in Fig. 2, the grooves are separated only by avery short space, sa for about an inch, from the ends of the lan so that immediately upon the explosion of the charge, and initial forward impulse of the projectile the lands of the n will take. into the grooves, as shown in By this arrange#- ig. 3. The sealmg contact heretofore spoken of is obtained V ooves and lands, so that the passage .escape of flame and Y ofsmall by the 'close and" ti'glt nter-fitting of u r wi closed practically air-tight against Athe gas. Inthecaseofguns caliber Asuch closure may be obtamed Aas will-be hereafter referred to, by

. the exact mechanical interiitting of the steel lands within vthe steel grooves, but in-the case of larger ordnance where'the pressure isl .thereof and the lands of the gun. This j groove in any suitab e manner.

is preferably of copper and is desigby 7. It ma l. nate be secured in the guns, a filling or lining of some plastic, non- -metallic composition may be employed, if

` desired.'

In Fig. 2, the. projectile is shawn inthe before the charge is fired and in the en- Y arged detail of Fig. 3, it is shown as just begltgement of the ands and ginmng its engagement with the lands of the gun, one of these lands being shown as emedded in the copper lining 7. In Fi 4, the dotted lines 8 represent the edgeso the lands, showing the extent of projection of the lands into the cop er. As soon as such enooves takes place, the copper is compresse by the lands and spreads out, completely closing the bore of the and preventing the passag? of the as an flame'from the powder cham er over t e surface of the projectile and against the inner surface of the bore. continues its ,movement it will be given the pro er rotating motion by such engagement of t e grooves and lands. The immediate closure of the bore also prevents the melting of the copper and the long bearing surface obtained by the continuous lining on the- *Eart of the projectile in contact with the ore insures' the proper engagement of the grooves with the lands so a`s to obtain both the closing action and rifle motion, even with guns previously somewhat eroded. By thus insuring the closing of the bore, not

' only is erosion prevented but also the loss of velocity due to windage.

In F 5, a 9 is shown having lands 10 in whic gun ts a projectile 11, havin helical grooves 12, to engage the lands. v n this form, which may be used for of smaller caliber and of less pressure, t e grooves are `terial of the 1 to 4 may' e made an In small f As' the projectile' lining of suicient thic cut directly in' the steel or iron of the pro- 'ectile and .obtain the closing action merely y their close mechanical fit with the lands,

such fit being expressly made tight enoughto exclude the assage of as and me.

It is clear t at some c ngs in the malining of the pro'ectile shown in 1 "iwdm ming 1n ace o es in detil made viithprinciple of my inodsof securing such and other minor cha out departing from t vention. v

Having thus described my invention, what 1. Aprojectile for riiled having helical groovesextending-longltudinallg of the projectile and adapted to 4engage t e lands of the gun and having therein linings. of

softer material than the gun and providing grooves of less depth than the lands of the gun, sitantially as described.

'I claim isz- 2. A rojectile-for riiled guns havin helical lan -engaging grooves extending ongitudina y o t e projectile, and having a soft metal lining' therein, forming grooves of less depth than the lands of the gun, in which lining the lands ofthe are ada ted to be embedded, substantial y as descri ed.

3. A projectile for ried guns having landengaging ooves extending lon itu inall of the projectile and for '.he entir length oyf the part thereof 'of maximum diameter,

ooves being lined with soft metal providmg grooves of less depth than the lands of the gun, in which lining the lands of the gun become embedded, substantially. as described.

4. In acombination with a rifled'gun, a projectile therefor having helical land-engaging grooves extending throughout the ength o the part of the projectile of maximum diameter, said ooves having a soft ess to form grooves of vless de th than the lands of the gun so that the g willbe compressed and the lands be embedded therein when the lands enter the grooves, whereby the grooves and lands impart a rotary movement to the projectileand are t' htly sealed against the assage of as an flame between the projectile and ore of the gun, substantially as described. 

